HDQRS. U. S. ENGINEER BATTLN., ARMY OF THE POTOMAC, July 16, 1864.

Major J. C. DUANE,
Chief Engineer:

MAJOR: I have the honor to report the following engineer operations during the past twenty-four hours; Captain Harwood reports the redoubt near Spicer's as finished, with the exception of the gorge and some unimportant details; states that it could be occupied at once if the emergency required. A line of rifle-pits has been extended from the redoubt to the left of the Norfolk road. Slashing timber proceeds on the right and left. About one-third of the line of rifle-pits connecting the two redoubts (that near Spicer's and the one near the James house) has been completed, and progress is making at one points. Lieutenant Howell reports a four-gun half-sunken siege battery laid out on General Ayres' front, parapet twenty feet at base; flank twenty-four feet long, of same thickness; one traverse ten feet thick. Ground broken last night with 200 men. Lieutenant Cuyler report the revetment of a battery alongside of the one last referred to as completed, and the necessary thickness given to the parapet generally; some slight additional work required. Captain Gillespie reports the parapets of the batteries on General Griffin's right as increased to the proper thickness and the batteries ready for guns. Lieutenant Heap reports the rifle-pits supporting the battery at the Chieves house completed, extending to the woods on the right and nearly to the ravine on the left.

I am, very respectfully, your obedient servant,

G. H. MENDELL,

Captain of Engineers, Commanding.

WALTHALL STATION, July 16, 1864.

Captain FISHER,

Chief Signal Officer:

No indication of movements this a.m. Intercepted messages:

8.45 A. M.

Colonel BRENT,

Assistant Adjutant-General:

Two brigades infantry just passed open space to our left of Cobb's, going toward the enemy's front of Chesterfield; two gun-boats off Point of Rocks.

OPERATOR,

At C.

(Same to A. B.)

9.15 A. M.

A. B.:

Three regiments infantry just left Hare's house, going toward the enemy's left.

V. H. B.,

At D.

CHAS. L. DAVIS,

Captain, &c.